In a typical method for detecting abnormalities such as failures in circuit components and elements in an electric circuit, current, voltage, resistance, etc. of those spots which are supposed to be abnormal are measured by means of a tester, ammeter, voltmeter, etc. to detect abnormalities. A similar method is conventionally used to detect and diagnose abnormalities in an inverter drive control apparatus for drivingly controlling a motor by means of an inverter.
According to the aforesaid abnormality diagnosis method using the tester and the like, measurement must be carried out after removing covers for supposedly abnormal spots and other members that hinder the measurement. If no abnormalities are detected as a result of the measurement, other spots must be measured in like manner after reassembling the removed member. Thus, the detection and diagnosis of abnormalities require much time and labor.